title: Enhanced immune defences in Pacific white shrimp (Litopenaeus vannamei) post-exposure to a vibrio vaccine.
abstract: This study was conducted to determine if exposure of shrimp, Litopenaeus vannamei, to a commercial anti-vibrio vaccine caused changes in antibacterial and cellular (phagocytosis) defences. Shrimp post-larvae were administered either Vibromax™ vaccine or a blank preparation. Whole body homogenates were prepared before (day 0), during (day 10) and after (day 20) vaccination and incubated with a selection of pathogenic vibrios. Homogenate from day 0 animals showed natural antibacterial activity towards Vibrioanguillarum which was significantly enhanced for bacteria-exposed shrimp at 10 days post-challenge. This effect of the vaccine was short-term in its duration. No antibacterial activity was observed in day 0 shrimp homogenate against Vibrio alginolyticus but it was significantly enhanced for both vaccinated and blank-vaccinated shrimp by day 10. No natural or inducible antibacterial activity was observed against Vibrio harveyi at 0, 10 or 20 days post-challenge. To determine if prior exposure of shrimp to inactivated vibrios results in elevated hemocyte phagocytic activity, juveniles were injected with either a mixture of formalin-inactivated vibrios or saline. Hemocyte monolayers made from these shrimp were overlaid with a 1:1 mix of Bacillus subtilis and these vibrios. Hemocytes from vibrio-exposed animals showed elevated levels of internalised vibrios compared with those from the saline injected group. These studies show selectively enhanced cellular defences of shrimp following 'vaccination'.
authors.affiliation: Centre for Sustainable Aquaculture Research, Department of Biosciences, Swansea University, Swansea SA2 8PP, UK.
authors.forename: Adam
authors.initials: A
authors.lastname: Powell
authors.forename: Edward C
authors.initials: EC
authors.lastname: Pope
authors.forename: Fiona E
authors.initials: FE
authors.lastname: Eddy
authors.forename: Emily C
authors.initials: EC
authors.lastname: Roberts
authors.forename: Robin J
authors.initials: RJ
authors.lastname: Shields
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Francis
authors.forename: Patrick
authors.initials: P
authors.lastname: Smith
authors.forename: Sylvie
authors.initials: S
authors.lastname: Topps
authors.forename: Jim
authors.initials: J
authors.lastname: Reid
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Rowley
mesh_terms: D000818:Animals; D001428:Bacterial Vaccines / Q000008:administration & dosage*; D054884:Host-Pathogen Interactions; D007113:Immunity, Innate / Q000276:immunology*; D033561:Penaeidae / Q000276:immunology* / Q000382:microbiology; D010587:Phagocytosis / Q000276:immunology; D014611:Vaccination; D015164:Vaccines, Inactivated / Q000008:administration & dosage; D014735:Vibrio Infections / Q000276:immunology / Q000517:prevention & control*; D044149:Vibrio alginolyticus / Q000276:immunology*
chemical_list: D001428:Bacterial Vaccines; D015164:Vaccines, Inactivated